fetch: make --prune configurable

Without "git fetch --prune", remote-tracking branches for a branch
the other side already has removed will stay forever.  Some people
want to always run "git fetch --prune".

To accommodate users who want to either prune always or when fetching
from a particular remote, add two new configuration variables
"fetch.prune" and "remote.<name>.prune":

 - "fetch.prune" allows to enable prune for all fetch operations.

 - "remote.<name>.prune" allows to change the behaviour per remote.

The latter will naturally override the former, and the --[no-]prune
option from the command line will override the configured default.

Since --prune is a potentially destructive operation (Git doesn't
keep reflogs for deleted references yet), we don't want to prune
without users consent, so this configuration will not be on by
default.

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael Schubert <mschub@elegosoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/remote.c b/remote.c
index 68eb99b..89be211 100644
--- a/remote.c
+++ b/remote.c
@@ -148,6 +148,7 @@ static struct remote *make_remote(const char *name, int len)
 	}
 
 	ret = xcalloc(1, sizeof(struct remote));
+	ret->prune = -1;  /* unspecified */
 	ALLOC_GROW(remotes, remotes_nr + 1, remotes_alloc);
 	remotes[remotes_nr++] = ret;
 	if (len)
@@ -419,6 +420,8 @@ static int handle_config(const char *key, const char *value, void *cb)
 		remote->skip_default_update = git_config_bool(key, value);
 	else if (!strcmp(subkey, ".skipfetchall"))
 		remote->skip_default_update = git_config_bool(key, value);
+	else if (!strcmp(subkey, ".prune"))
+		remote->prune = git_config_bool(key, value);
 	else if (!strcmp(subkey, ".url")) {
 		const char *v;
 		if (git_config_string(&v, key, value))